• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.372-381
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• 1985

Oxo molybdenum (V) complexes of substituted 8-quinolinols were synthesized and characterized by means of the investigation of elemental analysis, infrared spectra, electron spectra, electric conductivity and mass spectrometry compared with oxo molybdenum (VI) complexes. Oxo molybdenum(V) complexes were nonelectrolyte and one strong band of stretching mode of molybdenum and terminal oxygen appeared approximately $940cm^{-1}$. Oxo molybdenum(VI) complexes gave two peaks corresponding molybdenum containing ions, a molecular ion (I) of a 2 : 1 (ligand : metal) chelate and a fragment ion (II) of a 1:1 chelate due to the loss of ligand radical from ion (I). Molybdenum(V) complexes were observed the fragment ion(II) of a 1 : 1 chelate partly. The electronic spectra corresponding to d-d transition and charge transfer transition were observed and interpreted.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.460-465
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• 2004

Hydrofluoric acid has been used as a novel stripping agent for molybdenum(VI) after its extraction with Cyanex 301. In the extraction step, the effects of parameters such as type and initial concentration of acid, type of diluent, extractant concentration, metal concentration and temperature have been studied. In the stripping step, the effects of various stripping agents on stripping efficiency have been investigated. Hydrofluoric acid has been chosen as an effective stripping agent, and the effects of concentration of hydrofluoric acid, stripping time, volume of hydrofluoric acid and the number of stages of stripping have been studied. Molybdenum(VI) has been effectively separated from a large number of elements in binary mixtures, with a very high tolerance limit. Finally, the optimized method has been extended for the analysis of Mo(VI) in spent molybdenum catalysts.

• Bulletin of the Korean Chemical Society
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• v.32 no.10
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• pp.3687-3691
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• 2011

Ion exchange experiments of molybdenum(VI) from strong HCl and $H_2SO_4$ solution have been done to investigate the existence of anionic complexes. The concentration of HCl and $H_2SO_4$was changed from 1 to 9 M. From the data on the complex formation of molybdenum in aqueous solution, a new distribution diagram of Mo(VI) was constructed in the pH range from zero to 10. AG 1 X-8, an anion exchange resin, and Diphonix, a cation exchange resin were used in the loading experiments. Ion exchange results indicate that anionic complexes of Mo(VI) begins to form from 3 M HCl and 1 M $H_2SO_4$ solution and the tendency to form anionic complexes is stronger in HCl than in $H_2SO_4$ solution. Our results can be utilized in the analysis of Mo(VI) in strong acid solution and in the design of a process to separate Mo(VI).

• Bulletin of the Korean Chemical Society
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• v.20 no.9
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• pp.1105-1107
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• 1999

• Bulletin of the Korean Chemical Society
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• v.19 no.5
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• pp.587-590
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• 1998

• Resources Recycling
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• v.27 no.4
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• pp.44-49
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• 2018

$MoO{_4}^{2-}$ is the stable chemical species of Mo(VI) in alkaline solution. In the pH range of 2 to 6, condensation polymerization between $MoO{_4}^{2-}$ and hydrogen ion results in the formation of various polyanions of Mo(VI). Polycations of Mo(VI) begin to form when solution pH is less than 2. As the concentration of inorganic acid increases, polycations of Mo(VI) can react with the anion of the inorganic acid, resulting in the formation of heteranions of Mo(VI). The distribution of Mo(VI) species at pH < 6 depends on the concentration of Mo(V) and inorganic acid. In order to analyze the solvent extraction and ion exchange data on Mo(VI) from concentrated inorganic acid solution, it is necessary to elucidate the nature of Mo(VI) complexes.

• Bulletin of the Korean Chemical Society
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• v.15 no.9
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• pp.766-771
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• 1994

A number of molybdenum(VI), -(V), and -(IV) oxo complexes with S-methyl 3-(2-hydroxyphenyl)methylenedithiocarbazate and its derivatives as the ONS-donor metal-binding substrate are synthesized. The Mo(VI)-dioxo complexes are cis-dioxo Mo$O_2$L(D), where D is solvent molecules such as MeOH, DMF, Py(pyridine), DMSO, and ${\gamma}$-Pic(${\gamma}$-picoline). The Mo(V)-oxo complexes are of the type (PyH)[MoO(NCS$)_2$L] with an octahedral geometry. The Mo(IV)-oxo complexes, MoOL are derived from corresponding Mo(VI)-dioxo complexes by oxo abstraction with PP$h_3$. The complexes are characterized by IR, $^1$H-NMR, UV-Vis spectroscopy and cyclic voltammetry. On the basis of ligand displacement reaction, the qualitative order of D binding for Mo$O_2$L(D) complexes is also discussed.

• Journal of the Korean Chemical Society
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• v.29 no.3
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• pp.226-232
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• 1985

Dioxomolybdenum(VI) complexes, MoO$_2$(H-Sal-R)$_2$, R; arylamines, have been synthesized by reactions of dioxobis (salicylaldehydato) molybdenum(VI) with various primary amines. These complexes have been characterized by electric conductivity and spectroscopic studies. Infrared, uv-vis, and proton nmr spectra show that the complexes are six-coordinated with cis-MoO$_2$ group. And mass spectra indicates that the combining ratios for Mo (VI)-ligand are 1 : 2. They are yellow, stable for a considerably long time in the atmosphere at room temperature and slightly soluble in alcohol, dichloromethane and dimethylformamide but insoluble in benzene, ether and carbon tetrachloride.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1819-1822
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• 2008

• Journal of the Korean Chemical Society
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• v.12 no.4
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• pp.146-149
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• 1968

A new chelate compound, tris(8-bydroxyquinolino)molybdenum(III), [$Mo(C_9H_6ON)_3$], has been prepared by the method of electrolytic reduction of the acidic molybdate solution. Thermal decomposition products of the chelate has been studied by DTA and TGA method. It is concluded that the decomposition product is a yellowish green colored bis(8-hydroxyquinolino)dioxo molybdenum(VI), [$MoO_2(C_9H_6ON)_2$].